After an exciting wait my partners Christmas present has arrived and I am wanting to get it engraved, the original engraving I would have liked, le do thaobh go brách, is too long so I am having to have a rethink. Unfortunately my knowledge of the Irish language is very limited so i am relying on google translate which seems to be less that accurate at times and wanted to check that “grá duit níos mó” does actually ttanslate to “love you more”.

Feeling a little like an imposter joining for advice but I really want his gift to be perfect. Thanks for reading and for any advice

After an exciting wait my partners Christmas present has arrived and I am wanting to get it engraved, the original engraving I would have liked, le do thaobh go brách, is too long so I am having to have a rethink. Unfortunately my knowledge of the Irish language is very limited so i am relying on google translate which seems to be less that accurate at times and wanted to check that “grá duit níos mó” does actually ttanslate to “love you more”.

Feeling a little like an imposter joining for advice but I really want his gift to be perfect. Thanks for reading and for any advice

No, that's not grammatical, and unfortunately fixing it will undoubtedly make it longer. Short verbal expressions which are possible in English (which is perhaps the most flexible of languages) usually do not translate well into short expressions in Irish, because Irish is much more noun-oriented than verb-oriented.

If you need something brief, here's one possibility which is pretty brief:

Leatsa go deo ["go deo" is essentially the same as "go brách", but a bit shorter]Yours forever [it can also mean "With you forever"]

You could also use this, although it's a bit cryptic in Irish:

Grá duit go deoLove for you forever

_________________I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

Usually, the pronoun tú/tusa is next to the copula in identification sentences. But in "Mo ghrá thú" it is last. This is only possible by a compulsary omission of "is", hence "Is mo ghrá thú" sounds very strange. (The "is mo X" part, i.e. a definite noun phrase directly following the copula, is impossible. And "Is é mo ghrá thú" doesn't even make more sense. It is impossible, too. No, the only correct form is "Mo ghrá thú".

Mo ghrá thú! Is tú mo ghrá.(Is) tusa mo ghrá.

You can omit "is" in the last construction, but I prob. wouldn't do so, though.

I don't know the full etymology of the use of thú in such cases, but it essentially carries the meaning of "to you", "for you" or "on you", without the preposition actually being stated. There is a theory that the Australian expression "Good on yeh" is a translation from the Irish "Maith thú", which uses thú in this way (Irish was spoken by many Irish prisoners transported to Australia).

_________________I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.